CrispyChips :
"3D vision" will not work with the 290's. AMD has their own implementation called "Eyefinity"
EDIT: or are we talking about Stereoscopic 3D?
You are wright that it won't work, but AMD's version is called HD3D, which is an open standard. They really don't give much support to it, however, and you'll need to use Tridef software for it to work. Unfortunately, it is a huge CPU hog from my experience.
I'd recommend you stick with Nvidia if 3d Vision is your thing.